With the grounding of the Kulluk, regulators will be endangering a valuable environmental resource if they don't reexamine what's needed to drill safely under the most challenging conditions.

There's at least a tiny bit of good news in the grounding of an oil rig in the Beaufort Sea off Alaska: As of midday Wednesday, the Kulluk, which ran aground near Kodiak Island, didn't appear to be leaking fuel, thanks to its double hull of 3-inch-thick steel. We've learned some things about oil and safety since the Exxon Valdez. But the overwhelming lesson of the Kulluk, which broke free of boats trying to tow it to Seattle after its first season in the Beaufort Sea, is that for all the precautions taken by Royal Dutch Shell, neither the company's executives nor federal regulators were fully prepared for the hazardous conditions in the Arctic.

The rig, which has no propulsion system of its own, was being towed for maintenance before beginning its next season of drilling in the spring. That's supposed to be the routine: a spring-summer drilling season that ends Oct. 31, with the rig then towed to milder climates for the winter. But there were delays because of weather and equipment problems, including a lack of de-icing capability on the helicopters that were supposed to transport most of the crew off the rig before it could be moved. As a result, the towing didn't begin until the difficult days of winter.

It's the most recent in a long list of problems that Shell has encountered. Its failure to build an Arctic-worthy containment dome and spill-response barge kept it from drilling this year to depths where it might reach oil. In November, the U.S. Coast Guard found serious deficiencies involving pollution controls and crew safety in the Noble Discoverer, the drilling ship Shell used in the Chukchi Sea.

At least the Noble Discoverer was gone from the Chukchi by that time, because the drilling season there ends Sept. 24, before ice, high seas and storms have a greater chance of imperiling operations. At a minimum, taking into account the problems the Kulluk encountered in late October, federal regulators should consider a similar date for the Beaufort Sea.

But that would only begin to address the issues. The grounding of the Kulluk occurred within 50 miles of a major Coast Guard facility, allowing for a quick response. But what if the same problems had been encountered 800 miles away? In just the first season of Royal Shell's Arctic operations, the region already has proved to be a far more perilous place for oil exploration than proponents foresaw. The rigs probably should not head back to the Arctic seas this spring; federal regulators will be endangering a valuable and fragile environmental resource if they don't reexamine what's needed to drill safely under the most challenging conditions.